Leaky roof

[tifosi77]

So ever since we bought our current house we've had problems with water penetrating into our roof. We have a roof-mounted HVAC, and since the first leak happened after prolonged a/c use and was directly under the mounting point, that was the initial suspect. HVAC tech came out and said it looked good to him. Since then, we've had a few recurrences, and each time we have either a roofer or an HVAC person out they say there are no apparent problems with anything.

Now, we are experiencing a leak about 7'-8' downslope from the HVAC directly over our dining room table, about 3' from the edge of the roof. When it starts, it's as if someone is pouring water through the ceiling for a minute or so, rather than a drip-drip-drip. It's as if something has over filled and there's runoff.

HVAC people say there's sufficient drainage from inside the unit, roofers say there are no dodgy shingles. Yet it still rains in my dining room. WTF?

[dodint]

I got you, guy:

Spoiler:

[MWB]

Obvious question, but was it raining? If not, I don't see how it would be anything but the ac unit, unless you have plumbing that runs through the ceiling. I assume it's a one story house though.

[tifosi77]

It has happened during prolonged a/c use in the summer and during periods of no a/c use and heavy rain. The two most current leaks have happened after several hours of steady rain. Like I say, it's as if an overflow pan or something has spilled, because the initial penetration into the house is like a faucet of water for a minute or so without any sort of build up or warning.

Yes, 1-story house. AFAIK, all plumbing in underneath the house.

[PensFanInDC]

Sounds like a condensate pump might not be working. That should be pumping water out of the pan and into a drain of some sort.

Does this happen every time it rains or the AC runs for prolonged periods? It could be the sensor that is supposed to start the pump. If it is either of those things the good news is that it shouldn't be a very expensive fix.

[tifosi77]

It only happens after hours of prolonged a/c use (very common in the summer) or persistent rain (which usually happens like three times a year). I tend to agree with what you're saying PFiDC, but we've had guys from different HVAC companies out and all have said the unit is tip top. But I don't know if they have checked that sensor.

[PensFanInDC]

Well it takes a VERY long time to generate enough condensation through using the AC to cause an overflow (assuming the pump is not working) so that makes sense. The condensate pump is not actually part of the unit (in a lot of cases) so they may have not checked it at all. Although that would be rather stupid of a technician...

Can you access the roof yourself? Can you get a hose up there? If you want to be absolutely sure you can pump enough water into the pan to get it full. If the pump doesn't come on then you have your problem. Just be sure to take an empty bucket and a baster or something up with you to empty the pan.

On the other hand, since this is a roof top unit, there may not even be a condensate pump. The pan may have a drain pipe plumbed into it. If that is the case there may be something obstructing it.

[MWB]

I would go with the last paragraph above. Do you know where the drain pipe for the ac unit is? Can you check that for blockage?

[dodint]

I keep reading this as "Lesky roof"

Needs MOAR Jagr.

[BigMcK]

The outlet from our pipe is outside about 18 inches above a flowerbed. Our A/C unit is inside the garage, and we had a leak at the pan. The guy that does our annual service spotted the problem when he pulled about 4 feet of plant that had climbed into the pipe out from the outlet.

Problem solved and we now keep climbing plants away.

[tifosi77]

I would go with the last paragraph above. Do you know where the drain pipe for the ac unit is? Can you check that for blockage?

Yes, we have a drain pipe. I will run up and check for blockages.

[PensFanInDC]

If that is indeed the problem where may I send the bill to?

[tifosi77]

1313 Mockingbird Lane, attn H Munster, Mockingbird Heights, CA

[PensFanInDC]

Is that 90001 or 90002?

[Letang Is The Truth]

i thought this said lesky roof

[slappybrown]

Seems to me this is the Lesky roof thread

[tifosi77]

Roofer came out on Saturday. Some of the mastic surrounding a dormer vent 3' away from the HVAC was cracked, and he thought that was the possible intrusion site. He applied mastic to that and the base of the HVAC, so we'll see if that holds. If not, we're looking at a shingle-by-shingle repair. Woohoo.

[dodint]

Just move.